Influence of carrier and oxygen treatment on the catalytic behavior of supported platinum-gold alloys

摘要: Catalysts containing 15% loading of 4% Pt-Au alloy on silica or ..gamma..-alumina were prepared by co-reduction with hydrazine, reduced in hydrogen, and tested for activity n-hexane isomerization cyclization at 350/sup 0/C. The catalysts then subjected to two oxidation-reduction cycles, the same reaction. Over alumina-supported alloy, initial conversion was 2.9%/g catalyst selectivities approx. 90 5%, respectively. After treatment, 6.0%/g catalyst, 30 56%, silica-supported had similar selectivity as but did not change significantly oxidation-reduction. A comparison pure platinum carriers suggested that segregated from during oxygen treatment formed oxide, oxide migrated alumina surface where it separate particles reduction, unable ''wet'' particle forms bulk again, reduction.